Exhaust-box



H. SCHNEEBELI.

EXHAUST BOX.

APPLICATION FILED Nov.29, 1919.

Patented Dec. 27, 1921.

3 SHEETS-SHEET 1.

Inventor.' Perf/uga Schnee beh'.

, Attorney.

H. SCHNEEBELI.

EXHAUST BOX.

APPLlcATloN FILED Nov. 29. 1919.

OOO

Inventor Hugo S'cmece/ Jtorney.

H. SCHNEEBELI.

Patented De. 27, 1921.

3 SHEETS-SHEET 3.

I UNITED STATES PATEN'r OFFICE.

HUGO soinmrzintr,y or ooURREvoIE, FRANCE Specification of Letters Patent.' 'Patented Dec. 27, 1921.

Application led November 29, 1919. Serial No. 341,514.

' (GRANTED UNDER T111: rRovIsIoNs or'rm; V.ser "or MARCH a, 19'21, 41 sur. L., 1313.)

. To all lwhom it may concern."

A Be it known that I, HUGO SCHNEEBELI, of 28 Rue de Bcon', Courbevoie, Seine, F rance, engineer, have invented an Exhaust-Box, (for which I `have 'filed applications in France Nov. 18 1918, Patent Number 500,596 of1919; Oct. 22, 1918, Patent Number 500,509 of 1919,) of which the following is a full, clear, and exactdescription.

Writh the exhaust boxes fitted-up to now -to vinternal combustion engines for the pur-l pose of reducing the noise caused by explosions, the result sought' for is usually only imperfectly obtained. lIf the devices 'used prevent, to a certain extent,the perception of the noise, they generally produce a backpressure very prejudicious to Ithe efficiency Yof the motor.

Moreover, when these apparatus are Aused with high power motors, aeroplane motors for instance, they have a very seriousdisadvantage from the fact that lthey do not prevent the issue of the flames which thus permit of; following, at night, the aeroplane in its flight.

The present invention has for its object an exhaust box for explosion motors in gen` eral,-but more partlcularly devised 1n view of its application to aircraft, completely remedying lthe above mentioned disadvan: tages. v t

` This exhaust box is essentially characterized by the fact that it 'comprises three distinct zones or portions connected together,

. 1. A first zone, directly exhaust of thernotor, in which is produced and without egress of flame.

yin

charge` ofgthe burnt gases and producing ay the re-ignition of the unburnt gases coming from the motor.

2. A second zone formed by a serles of gas diffusion or division chambers,in which.

a notable portion of the burnt gases is discharged without noise in the 3. A third zone comprising a gas coolchamber, insuringA the complete discooling and division of these gases so high that their total discharge is insured without noise and without production of flames.

l The re-ignition zone of unburnt gases v ofthe fames.

`connected to the atmosphere c substantially comprises a conical nozzle act- 1ng asv gas injector, arranged inthe exhaust branch lfor these gases. The discharge of the gases through this injector produces, in the first portion of the apparatus, the entrance of air from the atmosphere, which spontaneously ignites the unburnt gases when they issue from the injector. The'gas diffusion chambers, forming the second portion of the apparatus, essentiallyv consist in a series of 'hollow ribs or gills, arranged all around the gas outlet tube and 4forming chambers communicating with this outlet tube; the faces of these various chambers'belng perforated Withopenings insuring the silent issue of t-he burnt gases in the form ,of thin sheets and he gas cooling chamber'is constituted by a series of tubes communicating at one of their ends with the inlet branch 4of the gases and opening freely in the atmosphere. These,

preventing the issue perature preventing them from being ignited when discharged.

Various methods of carrying this invention into practice are illustrated in the accompanying drawings in which: t

Figure 1 is a front elevation of an exhaust .box made according to 4this invenl tion.

Fig. 2v is a longitudinal vertical section on an enlarged scale, of the various constitutive elements of the exhaust box shown in Fig. 1. l

Figs. 3 to 6' are cross vertical 'sections made respectively on *lines AfA, B-B, C-C and D-D of Fi 2. y y

Fig. 7 is a front elevation of a second form of execution.

Fig. 8 is a longitudinal vertical section of the essential elements of the exhaust box shown in Fig. 7.

Fi 9 is a. cross vertical section made on line E of Fig. 8. i

Fig. 10 illustrates a modification in the construction of the exhaust box.

Fig. 11 is a longitudinal vertical section of a special arrangement of the air inlet chamber leading to the gas injector.

Referring more particularly to Figs. l to 6, itwill be seen (Fig. l) that the present exhaust box essentiallv comprises three portions or zones F. G. arranged one after the other and in which are successively and respectively eected:

1. The re-ignition of the unburnt gases driven off by the motor,

2. The cooling, diffusion and silent dispersion in the atmosphere, of a notable portion of the burnt gases, v,

30. Thef'total discharge of the burnt gases remaining in the apparatus, these gases being led outside in the form of thin streams canalized and cooled in such a manner as tov prevent the formation of flames atthe outlet of the apparatus.

The exhaust box-having the above mentioned characteristic features substantially comprises a branch a of suitable length and cross section. directly connected to the gas exhaust branch b of the motor and inter- 'nally provided, at the place where it is coni a chamber (Z adapted to allow the entrance of the air from the atmosphere into the branch a., around the injector c, for producing the spontaneous ignition of the unburnt gases driven off by the motor and ente-ring into the branch a through the injector c.

For that purpose, the chamber (l is provided with openings d1 preferably formed by tongues cut out in the walls of this chamber and suitably raised for `facilitating the entrance of the air in the chamber d during the displacement of the apparatus in the atmosphere. The interior of this chamber d is, on the other hand. in constant communication with the tube a through the openings al in the latter.

On the branch a and beyond the injector c are arranged hollow cooling ribs or gills e constituting gas diffusion and division chambers communicating with the branch a through the openings (1.2 in the latter. The faces of the cooling ribs or gills forming the chambers e are perforated with openings e also formed by tongues cut out in the gills andsuitably raised for allowing the air from the atmosphere, circulating on the surface of the gills during the displacementof t-he apparatus, to produce through the openings e1 in the 'gills the suction of the burnt gases circulatingin the vbranch a and their silent discharge in the atmosphere.

As will be seen in the drawings, these chambers e for the cooling and discharge of the burnt gases, constituting the zone G of the apparatus, are arranged about the entire periphery of the branch a which maybe provided with a suitable number of series of these chambers, according to the appli cations.

The last zone H ofthe exhaust box in which is produced the discharge of the burnt gases remaining in the branch a, substantially comprises a series of tubes of any suitable cross section, connected on a portion of their length only to the rear end of the central branch a closed by a conical bottom a5.

These tubesv f, which communicate with the tube a, throughout the length of the portion connected to branch a, are closed at their front end f1.

They are extended beyondv the branch a so as to constitute', in their rear portion.

tubes free from any attachment with thisbranch a and to permit a free circulation of air between them, thus insuring an energetic cooling of the tubes and of the gases circulating in the latter.

The rearends of the exhaust tubes f are provided with an opening f2 of, reduced section, insuring the division of the gases in thin sheets at their point of discharge, the lowering of the temperature of these gases. during their passage in the tubes f, preventing the production of flames through the outlet openings 7'2 of these tubes.

Figs. 7 to 9 illustrate a'second form of execution of the exhaust box, differing from -that above described simply by the special arrangement of the zone in which are produced the diffusion and the division in thinvsheets or streams of the burnt gases and the discharge of a notable portion of these gases in the atmosphere.

Referring to Figs. T and 8, it will be seen that this exhaust box comprises, as in the first case, a central gas inlet branch a. carrying. at the inlet end. a gas injector formed as above by a conical nozzle c1.

Beyond this injector, cooling chambers e2 are' arranged at intervals and in suitable number on the branch a with which the interior of these chambers 'is in constant communication through the openings (l2 of this branch a.

Each of these chambers e2 is constituted, in this second embodiment, by two truncated cones assembled on their large base and fixed at their small base on the branch d.

The walls of these chambers, which constitute circular cooling ribs or gills, are perforated with openings e3 obtained by cutting out, in these walls, tongues suitably yso '.35 Y vided-each ,with a spherical seat d3, d* fitting raised or bent for allowing the air succes` sively circulating on the opposite facesl of these gills, during the displacement ofy the apparatus, to produce through the openings e3 in these gills the suction of the burntl gases circulating in the branch af, and their silent discharge in the atmos here.v

The exhaust box a, ove described with reference to Figs. 7 to 9 is completed by a bundle of tubes f similar to that described in the lirst form of execution (Figs. ll tot).y

In the modification (Fig. 1 0), the exhaust :box comprises a branch a in which open the inlet tubesg, connected to the motor, ,for the ferent from those of the motor, the body-of the branch a is carried by 'collars' surroundi ing-the latter at a4, @tand for :fitting up the injectin cone c-and the air inlet chamber d,' .the devlce illustrated in Fig. l1, may be In this case, the large bases of each'of the conical portions of this chamber arenot connected the one to the other.' -They arev profreely in one another `so'as to thus constitute 'a ball joint; one, of the conical portions forming the front part of the chamber d is fixed, in this case, to the exhaust` gas inlet tube b directly connected tothe motor .and

the rear part of this chamber is secured on.

the branch' a.

'The operation 'of this.'l apparatus is as follows: .Suppose the exhaust box is fitted-Ito an aeroplane flying inthe. direction indicated by the arrow X, the air fr'or'nthe atmosphere enters, by reason", ofthe movement of this aeroplane, in thefjchamber d through its openings d1. :j j

TheI gas driven off bythe motor enters l violently inthe branch `,-passing through the injector c and producing, through the openings t1 of the branch a, the .drawing in of the air entering into thechamber ai.'

, If the whole of these gases is not entirely 1 burnt,vor'if a sudden reductionof speedl of the inotol` corresponding 'to van.'L lrqaortant' 'emission of unburnt gases takes'placeQthe fresh atmospheric air coming infcontactwith these hot, unburnt gases produces thecsponytaneous ignition of these gases'as soonV as( .they issue from the injector. f

.-.Th'e'products of the combustion then circulate within the branch m Their silent 'discharge Vwithout, egress of flames tothe exterior is obtained in the zone Grl in the following manner: f"

By reason 'of the rapid movement of the vaeroplane in the atmosphere,the air passes over the entire outer surface bf the chambers e; it results therefrom a partial vacuum at the outlet orifices e1 of each ofthem, thus drawing the products of combustion of the branch a into each of the chambers e, then to the exterior through the openings e1 of each ofthem.

The multiplicity of the openings a2 of the branch a; and of the openings e1 of each chamber e produces on the'one hand, the division of the gases intowthin land numerous vjets V whichvare cooled by theirpassage in the chambers e and insure, on the other hand, by reason ofv this division, their silent discharge. l v j The outside propagation of the flames is also avoided Vby means of the arrangement of the openings a2 andel whichr act onsaid flames as a metallic network and prevent the outside lre-ignition of the cooled and unburnt gases. j

The gases'relnaining in the branch a, beyond the'zone G are forced, by reason of the conical bottom 1,5 of this branch, to pass, through the openings a3, in the bundleof tubes f, from which they are discharged outside through the openmgs f2 in the form of thin jets; the temperatureof these burnt gases being sufficiently lowered, during their passage in thebundleof tubes f, for preventf ing there-ignition, at the' outlet, of the unburnt portions which maystill exist` in the body or massfof the exhaust -gases.

From thefforegoingpit will be seen that thevarious actions which are successively produced in the -zones F, .Grand H of the apparatus,-insure the total and silent issue of the exhaust gasesl of the motor, Without production or egress of iames to the outside, the `unburnt gases being spontaneously ignited in contact with the atmospheric air drawn into the central branch by the issue i 'through the injector of the gases driven oif by the motor any issue 4or outside production of flames is rendered impossible inthe middle zone G bythe action of the atmospheric air which, passing over ithe.. faces o f the cooling .I

chambers land `sucking a notable portion! of "the burnt gases, extinguishes those which might -be eventually-sucked', inI through' the openings of these chambers; the gasesremainin inthe central branch are finally discharged inthe atmosphere through outlet openings, of reduced crossv section, of, a bundle of tubes constantlv cooled by the surrounding air, so as to sufficiently lower the v'temperature ofthe gases for preventing their re-ignition at the outlet orifices of the bundle of tubes'. i

The above described constructional arrangements are, of course, given only by way of. example and it is obvious that several injectors might be arranged one after the other and that the number of gas cooling and diffusion chambers might also be varied according to the application, without departing thereby from the nature of the invention.

Claimsf l. An exhaust box for explosion motors, insuring the noiseless discharge of the gases from the motor without producing prejudicious back-pressure and preventing any egress or outside production of llames, essentially constituted by: (a) a gas inlet branch suitably perforated at its periphery and directly connected to the exhaust branch of the motor; (b) one or more gas injectors comprising one or more air inlet chambers for producing the re-ignition of the unburnt gases driven oli' by the motor; (c) a series of burnt gas diffusion and division chambers insuring the cooling of these gases and producing the silent'discharge of a notable portion of the said gases into the atmosphere without outside production of flames; (d) a bundle of independent tubes arranged at the rear end of the gas inlet branch and adapted to produce such a cooling of the burnt gases that their discharge through the outlet openings of the bundle of tubes is efected without producing flames.

2. Anexhaust box for explosion motors, insuring the noiseless discharge of the gases from the motor without producing prejudicious back-pressure and preventing any egress or outside production of flames, comprising: (a) a gas injector constituted by a conical nozzle at the entrance of the gas inlet branch, the said gas inlet branch being outwardly provided with a chamber the walls of which are perforated with openings `allowing the entrance of the air into this chamber and into the gas inlet branch with which the said chamber is in constant communication through openings of the said brancli,'tl1e admission of atmospheric air producing the re-ignition of the unburnt gases; (b) diffusion chambers constituted byhollow gills having no direct communication with each other and arranged about the inlet branch and communicating with the latter, the faces of the hollow gills being perforated for the purpose of allowing the divided and cooled combustion products being discharged in the forni of thin sheets. these combustion products being outwardly drawn or sucked by the air passing over the outer faces of the hollow gills; (c) a bundle of independent tubes formed of a series of tubes supported only on a portion of their length by the gas inlet branch and communicating at this portion with the said branch. the other portion of the length of these tubes being free from attachment so as to be subjected on all their faces to the cooling action of the surrounding air, the issue of the gases being effected through the rear end of the said tubes which present an opening of reduced cross-section.

3. In an exhaustv box for the engines of vehicles and the like, diffusion chambers comprising two truncated conical casings joined at their large bases and surrounding a. central pipe of the exhaust box. said casings communicating directly with the central pipe, and having in their walls openings so arranged that the motion of the vehicle will cause the external air to advance the exhaust gases through thecentral pipe toward the discharge end thereof.

The foregoing specification of my exhaust box signed by me this Tth day of November. 1919.

HUGO SCHNEEBELI.

In the presence of- HENRY T. WILCox. 

